Biology Exam Grade 11

Cell Cycle

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a series of steps during which the chromosomes and other cell material double to make two copies.

Mitosis

Where all of the cells chromatids are evenly divided and they move to opposite ends of the cell to form new cells for growth and repair of damaged tissue

Chromatids

Uncoiled Chromosomes

Chromosomes

A structure found inside the nucleus of a cell. Made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs

Centromere

a chromosome constricted region which separates it into a short arm and a long arm.

Prophase

Chromatin sondense and thickens, nuclear membrane and nucleus disappears, centriole migrate to opposite poles, spindle fibres start to form

Metaphase

Spindle fibres attach to centimetre, chromosomes guided to middle of the cell

Anaphase

Spindle fibres pull chromatids to opposite poles of the cell

Telophase

Chromatids reach opposite poles, begin to unwind

Cytokenesis

The cell divides all the cytoplasm and organelles then it forms new cell membranes

Meiosis

The process by which sex cells or gametes are made. This process is also called gameto genesis

Haploid

a cell that contains a single set of chromosomes

Diploid

the presence of two complete sets of chromosomes in an organism's cells, with each parent contributing a chromosome to each pair.

Autosome

one of the numbered chromosomes, as opposed to the sex chromosomes. Humans have 22 pairs of ________ and one pair of sex chromosomes

__**Spermatogenesis**__

**The process by which male testes germ cells undergo meiosis to form sperm. Each diploid primary spermatogonium forms two haploid secondary spermatocytes, which divide to produce four haploid sperm.** 

__**Oogenesis**__

The process by which a diploid oogonium germ cell in the ovary undergoes meiosis to form ovum. This results in one haploid ovum and three haploif polar bodies.

__**Fertilization**__

Occurs when a haploid sperm (N) enters a haploid egg (N). Fertilazation forms a diploid zygote. The zygote is the first somatic cell.

Sex Chromosome

type of chromosome involved in sex determination.

homologous Chromosome

The chromosomal pair which contains the maternal as well as the paternal chromatid of the same length and gene position, and are joined by the centromere

sex-linked inheritance

haracteristics (or traits) that are influenced by genes carried on the sex chromosomes.

crossing Over

Occurs during meiosis prohase I. When homologous chromosomes overlap and exchange portions o their chromatids.

Allele

Alternate forms of genes

Genotype

The genetic makeup of an organism due to the alleles present in the genes 

Phenotype

A particular physicial appearance produced by the alleles in a gene

Co-dominance

Both alleles are expressed at the same time,

Incomplete Dominance

Occurs when 2 alleles are equally domimant and the heterozygous individuals produce a new phenotype 

random assortment

Happens when pollen fertilizes ovum from a different plant

__**Law of Segregation**__

States that inherited traits are determined by pairs of genes and that each of the genes separates into separate gametes

__**Law of Independent Assortment**__

States that inheritance of one trait does not affect the inheritance of alleles for another trait 

Multiple Allele

Some traits have more than two alleles, creating more phenotypic combinations. Example Blood

Genome

The whole hereditary info of an organism that is encoded in the DNA

DNA

deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.

Mutation

alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA

Recessive

relating to a gene (= chemical pattern) that causes a particular characteristic only when it is passed on by both parents.

Dominant

An allele of a gene when it effectively overrules the other (recessive) allele.

Sex Linkage

Genes located on a sex chomosome

Non-disjuction

the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes.

Albinism

reduced amount of melanin, or no melanin at all.

muscular dystrophy

group of muscle diseases caused by mutations in a person's genes. Over time, muscle weakness decreases mobility, making everyday tasks difficult.

karyotype

an individual's complete set of chromosomes

Down Syndrome

a condition in which a person has an extra chromosome.

Gene Therapy

a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material.

genetic engineering

a process that uses laboratory-based technologies to alter the DNA makeup of an organism. This may involve changing a single base pair (A-T or C-G), deleting a region of DNA or adding a new segment of DNA

Segregation

describes how pairs of gene variants are separated into reproductive cells.

heterozygous

Express or show the dominant allele, the recessive allele is not able to be expressed

Homozygous

Pure breeding individuals (both dominant or both recessive)

Hybrid

An individual formed by mating between unlike forms, usually genetically differentiated populations or species.

Pedigree

A diagram of family history that uses standardized symbols.

hemophilia

an inherited bleeding disorder in which the blood does not clot properly

kingdom

***the second highest taxonomic rank, just below domain***.

domain

highest taxonomic rank in the hierarchical biological classification system, above the kingdom level.

taxon

each kingdom is subdivided into a series of progressively smaller groups

Taxonomy

The science of classifying organisms. Developed by Carolus Linnaeus. Used simple characteristics to identify species and organize them into groups.

phylogeny

a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor.

hierarchical classification

a system of grouping things according to a hierarchy, or levels and orders.

binomial nomenclature

the biological system of naming the organisms in which the name is composed of two terms, where, the first term indicates the genus and the second term indicates the species of the organism

morphology

the study of the size, appearances, and internal relationships of animals, plants, and microbes.

species

a group of organisms that can reproduce with one another in nature and produce fertile offspring.

Prokaryotes

organisms whose cells lack a nucleus and other organelles. Divided into two distinct groups; the bacteria and the archaea

eukaryote

any cell or organism that possesses a clearly defined nucleus.

autotroph

an organism that can produce its own food using light, water, carbon dioxide, or other chemicals.

heterotroph

an organism that eats other plants or animals for energy and nutrients.

Plantae

includes all the plants. They are eukaryotic, multicellular and autotrophic organisms.

Animalia

Largest kingdom, multicellular eukaryotes. Do not possess chlorophyll or a cell wall

Protista

Simple eukaryotic organisms. Mostly unicellular, most live in water, damp terrestrial environments or even as parasites.

Fungi

Eukaryotic organisms such as yeasts, moulds, and mushrooms. Contain a cell wall, and are heterotrophs.

Bacteria

single-celled organisms

Archaea

a group of prokaryotic life, lack cell nuclei and therefore prokaryotes

Virus

Do not have cells, can’t make protein themselves. Can’t use energy. Without hosts they are simple group of chemicals.

lytic cycle

A reproduction process, where the the virus attaches to the cell surface, and chemically recognizes the host. Then makes proteins and nucleic acids, using the host cell as a slave. New viruses are assembled, and new virus particles are released into the infected cells

Lysogenic Cycle

Where a virus can insert their genome into the host cell genome for long periods of time. These viruses are called proviruses. Can switch into lytic cycle

capsid

the protein shell of a virus particle surrounding its nucleic acid.

methanogens

Microorganisms that create methane as a byproduct of their metabolism

halophiles

microorganisms that require certain concentrations of salt to survive, and they are found in both Eubacterial and Archaeal domains of life

thermoacidophiles

microorganisms that have developed mechanisms to successfully persist in unusually hot, acidic environments

Coccus

a spherical-shaped bacterium

Spirilli

curved-shaped bacteria which can range from a gently curved shape to a corkscrew spiral

diplo-

a combining form used like a prefix meaning “double” or “in pairs.”

staphylo-

Cells arranged in clusters resembling grapes

Strepto-

Cells arranged in a chain

Gram stain      

a method of staining used to distinguish and classify bacterial species into two large groups (gram-positive purple and gram-negative pink).

binary fission

asexual reproduction by a separation of the body into two new bodies.

Conjugation

the process by which one bacterium transfers genetic material to another through direct contact.

pili

short, hair-like structures on the cell surface of prokaryotic cells.

transformation

specific process where exogenous genetic material is directly taken up and incorporated by a cell through its cell membrane.

endospore

A differentiated cell formed within cells of certain Gram-positive bacteria that are extremely resistant to heat and other harmful conditions and agents.

Antibiotic

Medicines that fight infections caused by bacteria in humans and animals by either killing the bacteria or making it difficult for the bacteria to grow and multiply

bacillus

rod-shaped, endospore-forming aerobic or facultatively anaerobic, Gram-positive bacteria;

protozoa

one-celled animals found worldwide in most habitats.

algae

a group of predominantly aquatic, photosynthetic, and nucleus-bearing organisms that lack the true roots, stems, leaves, and specialized multicellular reproductive structures of plants

slime moulds & water moulds

Fungus-like protists that grow as slimy masses on decaying matter. fungus-like protists present in moist soil and surface water; they live as parasites or on decaying organisms.

cilia

small, slender, hair-like structures present on the surface of all mammalian cells

flagella

microscopic hair-like structures involved in the locomotion of a cel

hyphae

The fine, branching tubes which make up the body (or mycelium) of a multicellular fungus

mycelium

the vegetative part of a fungus or fungus-like bacterial colony, consisting of a mass of branching, thread-like hyphae.

septa  

The two sides of the heart are separated by a thin tissue wall

zygospore

The spores produced by fungus and protists

Fruiting Body

spore-containing fungal structures. part of the sexual phase of a fungal life cycle.

lichen

a small group of plants of composite nature, consisting of two dissimilar organisms, an alga and a fungus living in a symbiotic association.

seed

the part that develops from the ovules after fertilization.