Chapter 15 - Genetics and inheritance

Question 1

Allele

Answer 1

Alternate forms of a gene that occur at a given point in a chromosome

Question 2

Co-dominance

Answer 2

when two different alleles both show up in the phenotype (immunoglobin A and B in blood groups)

Question 3

recessive sex linked inheritance

Answer 3

Red-Green colour blindness, Hemophilia, Duchenne type of muscular dystrophy

Question 4

Recessive autosomal inheritance examples

Answer 4

Cystic fibrosis, phenylketonuria (doesnt have enzyme to convert phenylalanine)

Question 5

Dominant autosomal inheritance examples

Answer 5

Achondroplasia (dwarfism), huntingtons diease

Question 6

DNA profile

Answer 6

pattern of bands from a persons DNA that is revealed from electrophoresis

Question 7

genome

Answer 7

complete set of genetic information of an organism

Question 8

hemizygous

Answer 8

having no allele counterpart, occurs with alleles in the X chromosome in males as they dont have an allele counterpart on the Y chromosome.

Question 9

marker

Answer 9

segment of DNA with known characteristics, can be used to compare DNA profiles

Question 10

pedigree

Answer 10

family tree

Question 11

in terms of inheritance patterns. Genes

Answer 11

come in pairs, one from each parent

Question 12

phenotype

Answer 12

physical appearance of an individual from the expression of alleles for that gene

Question 13

severe genetic defects are rarely passed on to the next generation

Answer 13

often results in life threatening conditions that means die before reproductive age or cause severe diability so are too disabled to reproduce

Question 14

huntingtons disease

Answer 14

symptoms of difficulty in voluntary movements and cognitive decline start at age 40 and gets worse

Question 15

phenylketonuria

Answer 15

condition where body doesnt have the enzyme to convert phenylalanine amino acid into tyrosine, builds up to toxic levels in the body, causing mental retardation and seizures

Question 16

sex linked characteristics

Answer 16

determined by the genes carried on the X chromosome.

Question 17

duchenne type of muscular distrophy

Answer 17

X linked recessive disorder that leads to progressive muscle weakness

Question 18

patterns in sex linked inheritance

Answer 18

• mother is homozygous recessive then son will have the condition
• daughter has trait then father also has the condition

Question 19

DNA profiling

Answer 19

analysis of specific regions of a persons DNA to distinguish people from one another

Question 20

electrophoresis

Answer 20

technique used to reveal DNA profiles in a banded pattern
1. treat DNA sample with restriction enzyme to make staggard cuts when it comes across a specific base sequence
2. elecrophoresis where DNA fragments are separated on their size - DNA is negatively charged as of phosphate group in the backbone so smaller DNA peices move faster.
3. results in a pattern of bands called a DNA profile

Question 21

DNA profile

Answer 21

pattern of bands revealed by the process of electrophoresis

Question 22

DNA profile in identifying hereditary diseases

Answer 22

presence of alleles that can increase individuals chance of inheriting certain cancers or can cause hereditary diseases like cystic fibrosis or huntingtons disease

Question 23

DNA profile is used to trace ancestory

Answer 23

compare DNA profiles to see common alleles present as parents will pass alleles on to their children so will have some of the same bands

Question 24

marker

Answer 24

DNA segment of a sequence of bases with known characteristics, used for comparison in genetic testing

Question 25

DNA profile for forensics

Answer 25

individuals DNA should have identical DNA to the sample for it to match

Question 26

DNA profiling can determine risk of having a child with genetic disorder

Answer 26

detect if parents are carriers of specific genes associated with disorders or if genetic conditions are present in the fetus