biology review

Spindle

(biology) tiny fibers that are seen in cell division

If two pink flowered snapdragons are crossed, what is the chance that one of the offspring will have red flowers?

25%

If a mother is heterozygous for the hemophilia gene, and the father is normal, what is the chance that their MALE children will have hemophilia?

50%

In humans, if a person has the blood type genotype IAi, their blood type is

A BLOOD

Binary fusion

A form of asexual reproduction that produces identical offspring.

Trisomy

A genetic condition of having three chromosomes instead of two. The conidtion causes various birth defects

Gene

A segment of DNA that codes for a protein or RNA molecule.

If a human has one allele for the A blood antigen, and one allele for the B blood antigen, their blood type is.

AB blood

Homologous chromosomes

Chromosomes that are similar in size, shape, and genetic content

allele

Different forms of the same gene are referred

X-linked

Genes that are present on the X chromosome but not the Y chromosome

homozygous

If an individual has two alleles that are the same, the individual is _______ for the gene.

Heterozygous

If an individual has two different alleles for a given gene, the individual is ____ for the gene

Gene linkage

Inheritance of genes as a group because they are on the same chromosome

Does (Mitosis or Meiosis ) involve two cell divisions

Meiosis

Chromosome

The DNA and the proteins associated with the DNA

Recessive

The allele that is expressed only in homozygous and is completly masked in heterozygotes

pleiotrophy

The phenomenon in which one gene influences MANY traits is referred to as

short sature

The phenotype of an individual who is homozygous for the abnormal growth hormone gene (dd)is.

Chromatid

The two exact copies of DNA that make up each chromosome.

Homozygous recessive

When both alleles are recessive, the organism is said to be ________ ___________ for the gene.

recessive

When one allele is not expressed, and seems to be 'dominated' by the other allele, it is called the ________ allele.

Trisomy 21

a congenital disorder caused by having an extra 21st chromosome

Gamete

a mature sexual reproductive cell having a single set of unpaired chromosomes

Autosome

all animals have one pair of sex chromosome and a variable numbers of other chromosome, the other 22 chromosomes found in both sexes

dominant

an allele that can determine the phenotype of a heterozygotes completly, such that they are inditinguish from individuals homozygous for the allele, in the heterzygotges, the expression of the other(ressive) allele is completly masked

Haploid

an organism or cell having only one complete set of chromosomes

Autosome

any chromosome other than a sex chromosome

pedigree

are diagrams showing the genetic relationship among a set of related individuals

Centromere

area where the sister chromatids of a chromosome are attached

co dominance

both alleles are fully expressed , equal phenotype expression of both alleles when heterozygous

Homozygous

carrying two copy of the same allele of a given gene

Allele

different versions of a gene at a given locus

Cytokinesis

division of the cytoplasm

Zygote

fertilized egg

Alleles are alternate forms of the same

gene

epistatic genes

genes that affect the phenotype expression of other genes

Sex linkage

genes that are found on one sex chromosome but not on the other

Meiosis produces cells that are

genetically different

Homozygous chromosomes are chromosomes that

have the same gene in the same location

Heterozygous

having two different alleles for a trait

true breeding

homozygous organisms have two copies of the same allele for a given gene, hybrid( heterozygous) organism have two diffrent alleles for a given gene

Mitosis

in eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes

law of independent assortment

independent inheritance of two or more distinct traits

polygenic inherintance

inheritance that involves MANY genes acting together to influence a trait

test cross

is conducted to determine the gene condition of a single individual

incomplete dominance

neither allele is dominant

inhertance

occurs when a gene transmited from parent to the offspring, genetic transmition of characteristics

Diploid

of a cell or organism having two sets of chromosomes or twice the haploid number

Nondisjunction

of sex chromosomes in males produces sperm that have two sex chromosomes (xx,yy or yx) or that have no sex chromosomes at all (0)

Sex chromosome

one of two chromosomes of the 23rd pair of human chromosomes, which determine an individual's gender

self fertilization

pea egg cell in a pea flower fertilized by sperm from the same flower

Interphase

period of the cell cycle between cell divisions

Karyotype

the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number and arrangement and size and structure of the chromosomes)

incomplete dominance

the pattern of a heterozygous phenotype si intermediate between the two homozygous phenotypes

coedominance

the pattern of inheritance when heterozygotes express phenotypes of both of the homozygotes

Cell Cycle

the regular sequence of growth and division that cells undergo

cross-fertilization

when a sperm from one organism fertilizes eggs from a different organism

Non- disjunction is

zero of a particular chromosome or two of a particiular chromosome