Meiosis (Chpt 11 review)

Which of the following are differences between mitosis and meiosis? (HINT: there are multiple answers

• meiosis occurs in body cells and mitosis occurs in sex cells

• meiosis produces 4 daughter cells

  mitosis produces 2 daughter cells

• daughter cells from meiosis are genetically different from parents

  those from mitosis are the same

• daughter cells from meiosis have half the chromosomes of parent cells

  those from mitosis have the same number

Answer explanation

mitosis - in body cells

- 2 daughter cells

- genetically identical

to parents

- same number of

chromosomes

meiosis - in sex cells

- 4 daughter cells

- genetically different

from parents

- half (haploid)number of chromosomes

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Alleles are

• different types of genes

• traits

• pollinations

• hybrids

Answer explanation

Alleles are DIFFERENT types of genes.

gene = eye color

alleles = red & yellow eye color

Tags

NGSS.HS-LS3-2

Recessive alleles

• are identified by capital letters and only one is needed for trait to show (B)

• are identified by lower case letters and only one is needed for trait to show (b)

• are identified by lower case letters and two are needed for trait to show (bb)

• are identified by capital letters and two are needed for trait to show (Bb)

Answer explanation

RECESSIVE = LOWER case (b)

TWO are needed for trait to show.

In the example there is a 1 in 4 (25%) chance the child will be born with blue eyes b/c only one square has TWO recessive genes (bb)

When genes SEPARATE during gamete formation it is called

• dominance

• independent assortment

• probability

• crossing over

Answer explanation

Independent ASSORTMENT

The gene for one trait (like hair color) SORTS differently from the gene for another trait (height). The are SEPARATE from each other.

Why are genetic crosses (Punnett Squares) only a PROBABILITY and definite outcomes

• because of incomplete dominance crosses traits

• because asexual reproduction produces identical offspring

• because multiple alleles cause some traits

• because the environment and changes in genes can affect traits

Answer explanation

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Why did Mendel use pea plants?

• it is easy to control the crossing of the plants and they reproduce quickly

• they are unpredictable and pollinate independently

• there are only a few offspring so it is easier to collect data

• they only have one trait that can change

Answer explanation

COdominance is

• when one trait is more dominant that another

• when both traits are dominant so they both show up (white puppy with black spots)

• the trait is recessive so it requires two alleles

• neither trait is dominant so they mix (red & white plants form pink)

Answer explanation

codominance means BOTH traits show at the same time. They coexist or cooperate or keep each other company.

Gametes are

• sex cells with multiple alleles for each gene

• body cells with one allele for each gene

• body cells with multiple alleles for each gene

• sex cells with one allele for each gene

Answer explanation

Gametes are sex cells (egg or sperm) and contain ONE allele for each gene from the parent who produced it.

In the egg cell there is one allele for hair color (maybe blonde) and one for eye color (maybe blue), etc from mom.

In the sperm cell there is one allele for hair color (maybe brown) & one for eye color (maybe brown), etc from dad.

Tags

NGSS.HS-LS3-2

Incomplete dominance is

• when one trait is more dominant that another

• when both traits are dominant so they both show up (white puppy with black spots)

• the trait is recessive so it requires two alleles

• neither trait is dominant so they mix (red & white plants form pink)

Answer explanation

Incomplete dominance means NEITHER trait is dominate so

they "mix".

Black chicken & white chicken make gray chicken.

Humans have a DIPLOID number of 46 chromosomes the HAPLOID number for gametes is

• 12

• 23

• 92

• 46

Answer explanation

Diploid means TWO sets of chromosomes

Haploid is one set so it is HALF of the diploid number.