Life Sciencw Unit Flashcards
What is the Cell Theory?
A fundamental concept in biology stating that all living things are composed of cells, and cells are the basic unit of life, and all cells come from previously existing cells
Define Prokaryotic.
Organisms without a membrane-bound nucleus.
Define Eukaryotic.
Organisms with a membrane-bound nucleus.
What is the function of a Chloroplast?
Site of photosynthesis in plant cells.
What is a Cell Wall?
A rigid layer that provides support and protection to plant cells.
What is the role of a Nucleus?
Control center of the cell, containing genetic material.
What is a Vacuole?
A storage organelle in cells, often larger in plant cells.
What is the Cell Membrane?
A semipermeable membrane that surrounds the cell, controlling entry and exit of substances.
What is the function of Mitochondria?
Powerhouse of the cell, generating ATP through cellular respiration.
What is the Endoplasmic Reticulum?
An organelle involved in protein and lipid synthesis.
What is the function of Centrioles?
Involved in cell division, helping in the formation of spindle fibers.
What distinguishes a Plant Cell from an Animal Cell?
Plant cells have a cell wall and chloroplasts, while animal cells do not.
What is the Cell Cycle?
The series of phases that a cell goes through during growth and division.
Define Mitosis.
A process of cell division resulting in two identical daughter cells.
What occurs during Interphase?
The cell prepares for division by growing and replicating DNA.
What is Cytokinesis?
The division of the cytoplasm, resulting in two separate cells.
What are Chromosomes?
Structures made of DNA that carry genetic information.
What happens during Prophase?
Chromosomes condense and become visible; the nuclear membrane begins to break down.
What happens during Metaphase?
Chromosomes line up along the cell’s equatorial plane.
What occurs during Anaphase?
Sister chromatids are pulled apart to opposite poles of the cell.
What happens during Telophase?
Nuclear membranes reform around each set of chromosomes.
Define Meiosis.
A type of cell division that reduces the chromosome number by half, producing gametes.
What is Sexual Reproduction?
Reproduction involving the fusion of gametes from two parents.
What is Asexual Reproduction?
Reproduction without the fusion of gametes, resulting in offspring genetically identical to the parent.
What is Fertilization?
The process of fusion of male and female gametes.
Define Gamete.
A reproductive cell (sperm or egg) that carries genetic information.
What is a Zygote?
The fertilized egg formed from the fusion of gametes.
What is an Embryo?
An early stage of development in multicellular organisms.
What is a Fetus?
A later stage of development in mammals, following the embryo stage.
What does DNA stand for?
Deoxyribonucleic acid, the molecule that carries genetic information.
Define Unicellular.
Organisms made up of a single cell.
Define Multicellular.
Organisms made up of multiple cells.
What is a Haploid cell?
A cell containing one set of chromosomes.
What is a Diploid cell?
A cell containing two sets of chromosomes.
What is Pollination?
The transfer of pollen from male to female parts of a flower, can be cross or self-pollination.
What is an Egg in biological terms?
The female gamete.
What is Sperm?
The male gamete.
Define Fragmentation.
A form of asexual reproduction where an organism breaks into fragments that develop into new individuals.
What is Spore Production?
A method of asexual reproduction involving the release of spores.
What is Budding?
A form of asexual reproduction where a new organism develops from an outgrowth of a parent.
What is Vegetative Reproduction?
A form of asexual reproduction in plants that involves the growth of new plants from parts of the parent plant.
Define Binary Fission.
A method of asexual reproduction where a single organism divides into two identical organisms.
What is Parthenogenesis?
A form of asexual reproduction where an egg develops into an organism without fertilization.
What is Grafting?
A horticultural technique where tissues from one plant are inserted into those of another.
What is Cancer?
A disease characterized by uncontrolled cell division.
Define Carcinogen.
A substance that can lead to cancer.
What is a Tumour?
An abnormal mass of tissue resulting from excessive cell division.
What is a Clone?
An organism that is genetically identical to another organism.
Define Homozygous.
Having two identical alleles for a particular gene.
Define Heterozygous.
Having two different alleles for a particular gene.
What is a Hybrid?
Offspring resulting from the crossbreeding of two different species or varieties.
What is a Purebred?
An organism whose ancestors are genetically uniform.
What are Punnett Squares used for?
To predict the genetic outcome of a cross between two organisms.
What is a Dominant Trait?
A trait that is expressed in the phenotype even when only one allele is present.
What is a Recessive Trait?
A trait that is expressed in the phenotype only when two copies of the allele are present.
What are Sex Organs?
Organs involved in reproduction.
What is a Hermaphrodite?
An organism that has both male and female reproductive organs.
What is Contraception?
Methods used to prevent pregnancy.
What is Artificial Insemination?
A medical procedure used to treat infertility by introducing sperm into a female’s reproductive system.
What is In Vitro Fertilization (IVF)?
A procedure where an egg is fertilized by sperm outside the body.
What are Heritable Traits?
Traits that can be passed from parents to offspring.
What are Non-Heritable traits?
Traits that cannot be passed from parents to offspring.
Define Heredity.
The passing of traits from parents to offspring.
What is a Trait (Alleles)?
A characteristic of an organism that can be influenced by genetic factors.
What is a Gene?
A segment of DNA that codes for a specific trait.
Define Genotype.
The genetic makeup of an organism.
Define Phenotype.
The observable characteristics of an organism.
