T2: Biology

Anaphase

______ is the stage of mitosis/meiosis where the sister chromatids separate and are pulled towards opposite poles of the cell by the spindle fibers.

Chromosome

A __________ is a long, coiled-up strand of DNA that contains genes and other genetic information.

Throughout most of a cell’s life cycle, the DNA is unraveled. The DNA only condenses into ___________ during cell division.

Crossover

a process in which homologous chromosomes pair up and exchange genetic material.

________ occurs during the prophase I stage of meiosis.

Cytokinesis

a stage during mitosis or meiosis where the cytoplasm is divided, creating two daughter cells from one parent cell.

Diploid

a cell containing two complete sets of chromosomes, one from each parent.

The body, or somatic, cells of an organism (all cells other than the germ cells) are _________.

DNA

______ is a molecule that contains the genetic instructions used in the development and function of all living organisms. It is composed of nucleotides that are arranged in a double helix structure.

Dominant

a trait that is always expressed when it is present.

_______ alleles are usually represented by capital letters, such as F

Gamete

a mature, haploid reproductive cell that is created as a result of meiosis.

• Male cells that undergo meiosis produce _______ called sperm cells.

• Female cells that undergo meiosis produce polar bodies and ________ called egg cells (ova)

Genotype

The genetic makeup of an organism

The __________ of an organism refers to its complete set of inherited genes that determine its physical and behavioral traits.

Germ cell

a sexual reproductive cell that has the potential to develop into gametes.

______ cells include gametes as well as the diploid cells that divide to produce gametes

Haploid

a cell containing a single set of unpaired chromosomes.

_______ cells contain half the number of chromosomes as diploid cells. The gametes (sperm and egg cells) of an organism are ______.

Homologous chromosomes

a pair of chromosomes that are similar in length as well as gene and centromere position

Interphase

a phase in a cell’s life cycle where it grows, replicates DNA, and prepares for cell division

Meiosis

a type of cell division in which a parent cell divides twice, producing four daughter cells.

During _______, DNA is replicated only once, resulting in four daughter cells with half the amount of genetic material (haploid) as the parent (diploid)

Metaphase

a stage during mitosis and meiosis in which the chromosomes line up along the metaphase plate and chromosomes attach to spindle fibers

Mitosis

a type of cell division in which a parent cell divides once, producing two daughter cells.

During _______, the DNA is replicated once, resulting in two daughter cells that have exact copies of the parent cell’s DNA

Ovum

(egg cell) – a female germ cell involved in reproduction.

An _____ can grow into an organism after it is fertilized by a sperm cell.

Phenotype

the physical appearance of an organism.

Organisms with different genotypes can have the same __________. For example, an RR fruit fly and an Rr fruit fly both will have red eyes.

Prophase

a stage during mitosis and meiosis in which the nuclear envelope breaks down, the chromosomes condense, and centrosomes move to opposite poles of the cell.

Recessive

a trait that is not expressed when the dominant allele is present.

__________ alleles are usually represented by lowercase letters, such as f

Sister chromatids

two identical strands of DNA in a chromosome connected by a centromere

Sperm cell

a male germ cell involved in reproduction.

• Immature spermatids develop into ______ cells.

• _______ cells can fertilize egg cells during reproduction

Telophase

a stage during mitosis and meiosis in which the DNA unwinds and the nuclear envelope reforms around the chromosomes or chromatids

Zygote

a fertilized cell that forms from the fusion of an egg cell and a sperm cell

chromatin

NON-DIVIDING long strands of DNA that hold/carry genes

genes

provides information about who we are

ex. hair color, eye color

allele

half of a gene (meaning 1 half from mom or dad)

zygote

fertilized egg

centromere

the point where to chromosomes meet and connect

telomere

the cap found at the end of each chromosome arm

used to protect the chromosome when it duplicates but, it becomes shorter each duplication

DNA and mtDNA

DNA = composed of nucleotides and looks like a twisted ladder

mtDNA = DNA found in the mitochondria that comes from the maternal (mother) side

phosphate group

PO3H2

nitrogenous bases

Adenine (A)

Cytosine (C)

Guanine (G)

Thymine (T)

what does every chromosome have?

2 matching strands, a phosphate group, sugar on the outside, nitrogenous base in the center.

Watson, Crick, Wilkins, and Franklin

4 scientists produced a 1 page paper explaining DNA and proving that it has a helical shape

they won the nobel prize in 1962 (franklin didn’t get it because she died)

how did this experiement become possible?

Franklin (the best scientist in her field) received an x-ray of crystallography

chargaff’s rule

scientific bases are always paired with other specific bases

Adenine to Thymine

Cytosine to Guanine

somatic chromosomes

non gender cells

for example: bones and blood cells

gender chromosomes

female = XX, male = XY

histones

wrap around DNA to protect it

karyotypes

a chromosomal map that is used to study gender chromosomes

amino acids

protein molecules are made of amino acids, and our cells combine them to make different proteins (building blocks of proteins

what does DNA stand for?

deoxyribonucleic acid.