Q1 Review

Q1 Review: Cell Theory, ​Animal Cells, Plant Cells, Levels of Biological Organization in plants, Plant Homeostasis, Plant Responses

• Made first microscope​

• Coined the term "cell"​

• Plants made of cells​

• Animals made of cells​

• Cells come from pre-existing cells​

What they did​

• Leeuwenhoek

• Hooke

• Schleiden

• Schwann

• Virchow​

Scientists​

​History of Cell Theory

Cell Theory​

​The cell theory states:

• All living things are composed of cells.

• Cells are the basic units of structure & function

in living things. (The cell is the basic unit of life)

• All cells come from pre-existing cells.

Multiple Choice

Each student in a study group wrote an explanation of cell theory using their own words.

Which explanation of cell theory is not correct?

• Cell theory states that all organisms are made of one or more cells.

• According to cell theory, everything on Earth, both living and nonliving, is made

  of cells.

• Cell theory states that all cells come from other cells.

• According to cell theory, cells are the basic unit of life, and carry out functions such as obtaining energy from food and producing waste.

Multiple Choice

An amoeba is a microorganism composed of just one cell, while a pear tree is composed of about 15 trillion cells.

Which statement is not true, according to cell theory?

• Like an amoeba and a pear tree, all organisms are composed of one or more cells.

• The cells in both an amoeba and a pear tree carry on similar functions such as obtaining energy from food, producing waste, and reproducing.

• Cell theory refers only to organisms made of just one cell, like an amoeba.

• The cells in both an amoeba and a pear tree have similar parts such as cell membranes and nuclei.

Multiple Choice

Early Romans discovered that objects could be magnified through the construction and shaping of glass. For the past thousand years, this discovery has led to the construction and design of modern-day microscopes. The development of the microscope was used in the 17th and 18th centuries to observe cells and eventually develop “cell theory”.

Which of the following is the most basic explanation of “cell theory”?

• Every object in the universe is made of cells.

• Cells are made from atoms during chemical reactions.

• All cells are identical.

• All living things are made of cells.

Organelles and their functions​

• Nucleus - Brain of the cells, contains the DNA

• Cytoplasm - Jelly like fluid that holds the organelles

• Mitochondria - MIGHTY, provides the POWER to the cell

• Cell Membrane - Gatekeeper of the cell, allows things to go in and out

• Cell wall - Gives plant cells support and structure

• Chloroplast - where photosynthesis occurs in plant cells

• Vacuole ​- larger in plant cells, holds water and nutrients

Animal cell

Vs. Plant cell​

​Animal cell Vs. Plant cell

Multiple Choice

Organelle ____ is responsible for the process of photosynthesis in Cell A.

• 4 - chloroplast

• 4 - nucleus

• 4 - mitochondria

• 5 - vacuole

Multiple Choice

The diagram shows the interior of a plant cell, with its different organelles. Biologists have identified the structure and function of each organelle.

Which statement correctly describes the difference between the structure and function of Organelle B?

• This organelle processes energy for the cell.

• This organelle is surrounded by two membranes and contains many proteins. It

  contains genetic information for the cell.

• This organelle is a sac-like structure surrounded by a membrane. Its function is to store water and other substances

• This organelle is composed of an outer membrane, and an inner membrane with many folds.

Multiple Choice

Organelle ___ regulates the movement of substances in and out of Cell A.

• 6 - cell wall

• 6 - cell membrane

• 6 - chloroplast

• 6 - vacuole

Multiple Choice

What organelle has an outer membrane and a folded up inner membrane?

• chloroplast

• cytoplasm

• nucleus

• mitochondria

Multiple Choice

What organelle is green, has a double outer membrane, and has smaller structures inside?

• nucleus

• cytoplasm

• cell wall

• chloroplast

Multiple Choice

What organelle is large and looks like it is filled with water?

• cytoplasm

• vacuole

• cell wall

• nucleus

Multiple Choice

Organelle ____ in Cell B performs the same function as Organelle 6 in Cell A.

• 3 - cell membrane

• 3 - golgi body

• 4 - nucleus

• 5 - cell wall

Multiple Choice

The function of the plant cell structure shown in the enlargement is to –

• provide support for the cell.

• direct all the cell's activity.

• use energy from sunlight to make sugar.

• regulate substances that enter and exit the cell.

Levels of Organization in Plants​

​Levels of Organization in Plants

​Plant Cell -> Plant Tissue -> Plant Organ -> Plant Organ System -> Plant Organism

• Cells: Plant cell

• Tissue: xylem, phloem

• Organ: root, leaf, stem, flower

• Organ System: shoot system, root system

• organism: plant​​

​Example:

Plant cell -> phloem -> stem -> shoot system -> plant

​

​

Multiple Choice

A student found this picture in her friend's notes from science class.

What can she infer from this picture?

• It is a single cell because it has only one nucleus.

• It is a tissue because it is made up of similar cells.

• It is an organ because it is made up of different kinds of cells.

• It is an organ system because it is made up of different kinds of organs.

Multiple Choice

Clarissa drew this diagram to describe the levels of structural organization of a plant. She will list the cell as both the least specialized and the most numerous at the bottom of the pyramid.

Which of the following should she list in levels 1- through 4 on the diagram?

• 1 - organism 2 - organ system 3 - organ 4 - tissue

• 1 - organ system 2 - organism 3 - tissue 4 - organ

• 1 - tissue 2 - organ 3 - organ system 4 - organism

• 1 - organ 2 - tissue 3 - organism 4 - organ system

Tropisms​ - a plant's growth response to a stimulus

Plant responses to external stimuli​

​

• light (phototropism) - plants grow towards the light

• heat (transpiration) - plants maintain homeostasis by releasing water vapor when heat is present

• gravity​ (geotropism) - plant roots grow with gravity (down), plant's stem grows away from gravity (up)

Multiple Choice

A germinating seed is shown.

Refer to the image. In a germinating seed, the downward growth of roots and upward growth of leaves and

stems are the plant's responses to —

• water

• osmosis

• gravity

• soil

Multiple Choice

This plant is demonstrating...

• phototropism

• thigmotropism

• geotropism (gravitropism)

• hydrotropism

Multiple Choice

If a houseplant is placed near a window, the shoot tips will bend toward the direction of the light. This response is called -

• periodism

• geotropism

• negative tropism

• phototropism

Multiple Choice

Seeds that are planted upside down are still able to grow into mature plants. Which explanation best explains this phenomenon?

• The roots change into branches, and the branches turn into roots.

• The roots grow toward the force of gravity, and the shoots grow away.

• The plant will become a smaller version of a mature plant.

• Roots always grow toward the dark, and shoots grow toward the light.

Multiple Choice

A science class observes plant seedlings grow over a two-week time period, as shown in the image. When students record their data, they should describe the response the seedlings are showing as -

• taxis

• tropism

• stimulus

• hibernation

Multiple Choice

A student is investigating internal chemical stimuli in plants. She studies the cells of a plant under a microscope. She notes that the cells on the left side of the plant's stem are longer than the cells on the right side of the stem. She knows that this growth pattern is caused by the production of certain plant hormones.

What can you infer about the growing conditions of the plant based on its production of hormones?

• It is being grown in the dark.

•  A lamp is positioned on its left side.

• A window is near its right side.

• It has equal access to light on all sides.

Multiple Choice

This plant is demonstrating...

• phototropism

• thigmotropism

• geotropism (gravitropism)

• hydrotropism

​Motion in Plants

• Turgor Pressure

• Emergence of seedlings​

Multiple Choice

What internal stimulus would cause the plant to respond this way?

• A large amount of water in the stem

• Exposure to very little sunlight

• Exposure to too much sunlight

• A lack of water in the stem

Multiple Choice

What is the best description of what happened to this plant?

• The plant went from low turgor pressure to high turgor pressure after taking in water.

• The plant went from high turgor pressure to low turgor pressure after taking in water.

• The plant wilted and then magically came back to life.

• The plant stayed dehydrated.

Multiple Choice

When plants began to wilt they are experiencing a loss of water concentration inside their vacuoles. Therefore, there

is a greater amount of force being exerted by the cell walls on the plant. This effect is due to low____________.

• low oxygen level

• gravity

• turgor pressure

• photosynthesis

The emergence of Seedlings (Germination)​

​

Under the right conditions, seeds will absorb water and swell. When the seed absorbs enough water it will exert enough turgor pressure to rip open the seed coat. This will allow the seedling to emerge.​

Multiple Choice

In order for an embryo plant to emerge from a seed and grow into a seedling, the seedcoat must split open.

Which diagram illustrates the force exerted by turgor pressure to split open the seed coat?

Multiple Choice

What must happen for a seed to emerge from the soil as a seedling?

• The soil must erode and expose the seed to the sunlight.

• An animal searching for food must disrupt the soil.

• The seed must exert a force to push a shoot up through the soil.

• Another plant must die to make room for the new plant.