Chapter 11

Question 1

diploid

Answer 1

having two copies of every chromosome

these organisms carry two copies of each chromosome in their body cells

Question 2

haploid

Answer 2

having only one copy of every chromosome

sex cells in humans

Question 3

meiosis

Answer 3

specialized type of nuclear division that generates genetically unique haploid gametes
halves the number of chromosomes from 46 to 23

Question 4

zygote

Answer 4

fertilized egg
has 23 chromosomes from the egg
diploid
combo of haploid sperm fertilizing a haploid egg
carries 2 copies of every gene on 46 chromosomes

Question 5

somatic cells

Answer 5

body cells

all cells other than sex cells

Question 6

CTFR gene

Answer 6

gene that when mutated, caused cystic fibrosis

Question 7

independent assortment

Answer 7

the principle that alleles of different genes are distributed independently of one another during meiosis
not as a package
2^n possible arrangements (n=haploid number)

Question 8

dominant allele

Answer 8

allele that can mask the presence of a recessive allele (A=normal)

Question 9

recessive allele

Answer 9

allele that reveals itself in the phenotype only if a masking dominant allele is not present (a=cystic fibrosis)

Question 10

carrier

Answer 10

individual who is heterozygous for a particular gene of interest, & therefore can pass on the recessive allele without showing any of its effects

Question 11

testis

Answer 11

where sperm is located

Question 12

ovary

Answer 12

where eggs are located

Question 13

homozygous

Answer 13

having two identical alleles

Question 14

genotype

Answer 14

particular genetic makeup of an individual

Question 15

heterozygous

Answer 15

having two different alleles

Question 16

phenotype

Answer 16

the visable or measurable features of an individual

Question 17

Punnett square

Answer 17

diagram used to determine probabilities of offspring having particular genotypes, given the genotypes of the parents

Question 18

gametes

Answer 18

specialized reproductive cells that carry one copy of each chromosome (haploid)
sperm= male gametes
eggs=female gametes
sex cells

Question 19

cystic fibrosis

Answer 19

most common fatal genetic disease in US due to mutation in the CFTR gene located on chromosome 7
patients thick mucus clogs airways

Question 20

genetic variation

Answer 20

generated by meiosis in 2 different ways: 1. recombination (crossing over) 2. independent assortment

Question 21

recombination

Answer 21

event in meiosis during which maternal and paternal chromosomes pair and physically exchange DNA segments
crossing over
happens in meiosis 1
between non-sister chromatids

Question 22

Huntington’s Disease

Answer 22

disease caused by a dominant allele

Question 23

pre-implantation genetic diagonsis

Answer 23

detect and select embryos that do not carry defective alleles

Question 24

egg

Answer 24

female gametes

contains 23 chromosomes (haploid)

Question 25

sperm

Answer 25

male gametes

contains 23 chromosomes (haploid)