genetics

Question 1

define genetics

Answer 1

biology dealing with the study of genes, genetics, variation and heredity in organism

Question 2

what is genetics commonly know as?

Answer 2

the study of how traits are passed on

Question 3

what is a gene?

Answer 3

a gene is a basic unit of heredity that is located on the nucleus and is made up of DNA, and codes for specific protein

Question 4

how is chromosome formed?

Answer 4

-the DNA wraps around histone proteins
-8 histone proteins wrapped around the DNA makes up the nucleosome
-the nucleosome condenses to form chromatin fibers
-the chromatin fibers fibers condense to form chromosome

Question 5

define allele

Answer 5

different versions of the same gene where each allele comes from one parent

Question 6

define locus

Answer 6

specific position on a chromosome, where a particular gene is found

Question 7

what is a trait?

Answer 7

physical or behavioral characteristic that is passed on and is determined by genes

Question 8

what is a homologous chromosome?

Answer 8

pair of chromosome which is similar in shape, locus, centromere and chromosomal length but different versions of genes

Question 9

what is a heterozygous allele?

Answer 9

allele which has different version of the same gene

Question 10

what is a homozygous allele?

Answer 10

alleles which are the same version of the gene

Question 11

what is a dominant allele?

Answer 11

allele which suppresses expression of the alternate allele

Question 12

what is a recessive allele?

Answer 12

an allele that is masked by the dominant allele

Question 13

where can traits appear in dominant allele?

Answer 13

in heterozygous-Bb
in homozygous-BB

Question 14

where can traits appear in recessive allele?

Answer 14

only in homozygous-bb

Question 15

what is a genotype?

Answer 15

genetic makeup of an organism

Question 16

what is a phenotype?

Answer 16

observable characteristic resulting from genotypes interaction with the environment

Question 17

what did George Mendel do?

Answer 17

looked at seven traits of pea plants
seed-pod-stem-flower

Question 18

what is a monohybrid cross?

Answer 18

a genetic cross involving single pair of gene
eg: TT and tt

Question 19

define incomplete dominance

Answer 19

one allele is not completely dominant over the other so they blend

Question 20

define codominance

Answer 20

both alleles are expressed fully and separately

Question 21

what is a sex-linked trait

Answer 21

diseases that are caused due to the X chromosome carrying the recessive defective gene and therefore men are more susceptible to certain diseases

Question 22

what are the common disease in sex-linked traits?

Answer 22

1-colorblindess
2-hemphilia;blood cannot clot

Question 23

what are Mendel’s theory

Answer 23

1-dominance
2- segregation
3-independant assortment

Question 24

describe the dominance law

Answer 24

when pure parents with different traits of a particular gene are crossed, only the dominant trait will be passed on to the offspring

Question 25

describe the law of segregation

Answer 25

each gamete gets one allele for a particular gene

Question 26

describe the law of independent assortment

Answer 26

the allele of particular gene given to offspring is random and not dependent on another allele of a gene