bio exam 2

Question 1

What are the sequences on chromosomes that code for proteins called?

Answer 1

Genes

Genes are segments of DNA that determine specific traits.

Question 2

What do the two letters representing a gene indicate?

Answer 2

Genotype

Question 3

What is the term for the physical characteristic produced by genes?

Answer 3

Trait (phenotype)

Question 4

What are the two copies of a gene called?

Answer 4

Alleles

Question 5

Define homozygous.

Answer 5

Genes with two copies of the same allele

Question 6

Define heterozygous.

Answer 6

Genes with two different alleles

Question 7

What is a dominant allele?

Answer 7

An allele that needs only one copy for its effect to be seen

Question 8

What is a recessive allele?

Answer 8

An allele that needs two copies for its effect to be seen

Question 9

True or False: The effect of a dominant allele can mask that of a recessive allele.

Answer 9

True

Question 10

What is the Law of Segregation?

Answer 10

During meiosis, the two alleles for each gene separate as chromosomes move to opposite ends of the cell

Question 11

What is the Law of Independent Assortment?

Answer 11

Each chromosome is inherited independently of the others

Question 12

What is complete dominance?

Answer 12

Heterozygote exhibits the trait associated with the dominant allele only

Question 13

What is codominance?

Answer 13

Effects of both alleles are apparent in a heterozygote

Question 14

What is incomplete dominance?

Answer 14

Physical characteristic in between that of homozygous dominant and homozygous recessive

Question 15

What is pleiotropy?

Answer 15

When a gene influences more than one trait

Question 16

Fill in the blank: Variation in a trait, such as height or intelligence, involves _______.

Answer 16

Polygenic inheritance

Question 17

What is a characteristic of sex-linked genes?

Answer 17

Most genes on the X chromosome have no corresponding alleles on the Y chromosome

Question 18

Why are recessive phenotypes of X-linked genes more common in males?

Answer 18

Males have only one copy of the X chromosome

Question 19

What can cause breaks in chromosomes?

Answer 19

Chemicals, radiation, viruses

Question 20

What is chorionic villus sampling (CVS)?

Answer 20

A test that involves taking a small piece of chorionic villi to examine chromosomes

Question 21

What is amniocentesis?

Answer 21

A procedure where amniotic fluid is withdrawn to examine fetal cells

Question 22

What is the purpose of newborn genetic testing?

Answer 22

To screen for conditions like phenylketonuria (PKU)

Question 23

What is a pedigree?

Answer 23

A chart showing genetic connections among individuals in a family

Question 24

What distinguishes autosomal recessive disorders in pedigrees?

Answer 24

Unaffected individuals can have affected offspring

Question 25

What characterizes autosomal dominant disorders in pedigrees?

Answer 25

Affected individuals must have an affected parent

Question 26

How are X-linked recessive disorders typically inherited?

Answer 26

More often in males than females

Question 27

What are gonads?

Answer 27

Organs that produce gametes (testes and ovaries)

Question 28

What is the primary function of the testes?

Answer 28

Produce sperm and testosterone

Question 29

What is the primary function of the ovaries?

Answer 29

Produce eggs and hormones (estrogen and progesterone)

Question 30

What is the role of the epididymis?

Answer 30

Sperm maturation and storage

Question 31

What is oogenesis?

Answer 31

The development of eggs in the ovaries

Question 32

What triggers ovulation in females?

Answer 32

Luteinizing hormone (LH)

Question 33

What happens to the corpus luteum if fertilization does not occur?

Answer 33

It breaks down, leading to menstruation

Question 34

What is menopause?

Answer 34

The gradual cessation of female hormone production

Question 35

How do sex hormones affect behavior?

Answer 35

They can influence cognition, emotion, and reward processing