Life Cycle Unit Review

Front

Where do offspring's genes come from?

Back

Each parent gives them half of their genes.

Answer explanation

Offspring inherit genes from both parents, with each contributing half of the genetic material. This combination results in a unique set of genes for the offspring, making the correct answer "Each parent gives them half of their genes."

Front

Which of these traits is determined ONLY by heredity?

• body size
• eye color
• strength

Back

eye color

Answer explanation

Eye color is determined solely by genetics, making it the only trait in the options that is inherited. Body size and strength can be influenced by environmental factors and lifestyle choices.

Front

Which of these grows from a storage stem called a tuber? Strawberries, Potatoes, ferns

Back

Potatoes

Answer explanation

Potatoes grow from storage stems called tubers, which store nutrients. In contrast, strawberries grow from runners and ferns reproduce via spores, making potatoes the correct choice.

Front

Which of these grow from spores? fern, strawberries, potatoes

Back

fern

Answer explanation

Ferns grow from spores, which are reproductive cells that can develop into a new plant. In contrast, strawberries and potatoes grow from seeds and tubers, respectively, not spores.

Front

How many pairs of chromosomes do humans typically have?

Back

23

Answer explanation

Humans typically have 23 pairs of chromosomes, totaling 46 individual chromosomes. Each pair consists of one chromosome from each parent, making 23 the correct answer.

Front

What are considered the 'basic units of heredity'?

Back

Genes

Answer explanation

Genes are the basic units of heredity, responsible for passing traits from parents to offspring. They are segments of DNA that encode instructions for building proteins, which influence various characteristics.

Front

How do most animals begin the life cycle?

Back

As a fertilized egg

Answer explanation

Most animals begin their life cycle as a fertilized egg, which is the initial stage where the genetic material from both parents combines to form a new organism. This is a common starting point for many species.

Front

A trait is:

Back

a characteristic that makes one organism different from another

Answer explanation

A trait is defined as a characteristic that distinguishes one organism from another, making the correct choice the one that highlights this uniqueness, rather than focusing on heredity or the process of passing traits.

Front

What do plants need to make their own food?

Back

All three; water, sunlight, and carbon dioxide

Answer explanation

Plants need water, sunlight, and carbon dioxide to perform photosynthesis, the process by which they make their own food. Therefore, the correct answer is 'All three; water, sunlight, and carbon dioxide'.

Front

Which of the following animals hatch from eggs?
Options: Only amphibians and reptiles, All of the above; birds, fish, amphibians, and reptiles, Only birds and fish

Back

All of the above; birds, fish, amphibians, and reptiles

Answer explanation

The correct answer is 'All of the above; birds, fish, amphibians, and reptiles' because all these groups of animals reproduce by laying eggs, making them all egg-laying species.