Biology Ch. 8

Question 1

Prior to cell division, chromosomes consist of (1)_________ attached by a (2)____________.

Answer 1

1. chromatids
2. centromere

Question 2

What is codominance?

Answer 2

When both traits are expressed, meaning they are both dominant.
Ex: Red flower and white flower -> red flower with white dots

Question 3

DNA is replicated during what phase?

Answer 3

Interphase

Question 4

What three things happen in prophase?

Answer 4

The nuclear membrane breaks down,
chromosomes become visible,
and the centrioles move to the poles

Question 5

Mendel believed that organisms receive factors. These factors are _____?

Answer 5

Traits

Question 6

What is heredity?

Answer 6

traits being passed down through generations

Question 7

What is the difference between an autosome and a sex chromosome?

Answer 7

Autosomes are body cells, but sex chromosomes determine gender.

Question 8

What is a genotype?

Answer 8

The letters that represent an allele.

Question 9

Pairs of chromosomes that corry the same set of genetic info are _______?

Answer 9

Sister chromatids

Question 10

What do haploid gametes produce?

Answer 10

A zygote.

Question 11

What is a phenotype?

Answer 11

The physical presentation of trait

Question 12

What are the three principles of genetics that Mendel proposed?

Answer 12

Heredity, segregation, and independent assortment

Question 13

What is the relationship between DNA and chromosomes?

Answer 13

Chromosomes are made up of coiled up DNA

Question 14

What are the human sex chromosomes?

Answer 14

XX=female XY=male

Question 15

Who is most likely to carry a sex-linked trait? Why?

Answer 15

The male, because the males X chromosome automatically shows because the Y dosen’t have the trait. The XX is females has both have the sex-linked trait, so they are practically cancelled out.

Question 16

What is a dominant trait?

Answer 16

A trait that is usually expressed.

Question 17

What does mitosis produce?

Answer 17

2 genetically identical cells

Question 18

A cell spends most of its cell cycle in what phase?

Answer 18

Interphase

Question 19

Duplicated chromosomes comprise of two identical _____________?

Answer 19

sister chromatids

Question 20

What happens during interphase?

Answer 20

The cell gains organelles, grows, and the DNA is replicated.

Question 21

What is a section of DNA that codes for a particular trait or protein called?

Answer 21

Gene

Question 22

What do sex chromosomes do that autosomes don’t?

Answer 22

determine gender

Question 23

What is independent assortment?

Answer 23

When traits are dispersed and randomly assigned

Question 24

What’s a diploid

Answer 24

A cell with 2 chromatids per chromosome.

Question 25

Are punnett squares exact?

Answer 25

No, they are predictions for probability.

Question 26

What is a recessive trait?

Answer 26

A trait that is usually hidden

Question 27

Chromosomes are made of _________ wrapped around a histone.

Answer 27

DNA

Question 28

What's the difference between the terms 'homozygous' and 'heterozygous'?

Answer 28

Homozygous=same alleles TT or tt Heterozygous=different alleles Tt

Question 29

A cell with one set of chromosomes is called what?

Answer 29

A haploid

Question 30

What's incomplete dominance?

Answer 30

When traits are blended together.

Question 31

How many traits are expressed on a monohybrid punnett square?

Answer 31

one

Question 32

What does meiosis produce?

Answer 32

four genetically different sex cells

Question 33

What is a sex-linked trait?

Answer 33

A trait that is carried by a sex chromosomes.

Question 34

What is the difference between a gene and an allele?

Answer 34

A gene is a section of DNA that codes for a trait., and an allele is a letter that indicates a trait.

Question 35

How many chromosomes do humans have?

Answer 35

46

Question 36

What is segregation?

Answer 36

Traits have to be passed down through something.