Microorganisms and Biotechnology & Relationships of Organisms & Reproduction in Plants & Reproduction in Man & Inheritance

Flashcards in a question and answer format.

What is the smallest disease-causing particle known?

A virus

What two main components make up a virus?

Nucleic acid (DNA or RNA) and a protein coat

What is a host cell?

The living cell which a virus attacks

Name some examples of diseases caused by viruses that cannot be treated by antibiotics.

Influenza, HIV

Name the shapes of bacteria.

Cocci (spherical), Bacilli (rod-shaped), Spirilla (spiral-shaped)

What are the modes of life of bacteria?

Saprophytic (feed on decaying organic matter), parasitic (cause disease), autotrophic (manufacture their own food)

What is the mode of reproduction for bacteria?

Binary fission

Give examples of unicellular and multicellular fungi.

Unicellular: yeast; Multicellular: bread mould (Rhizopus)

What is the mesh of finely branching threads that make up fungi called?

Mycelium

What is the cell wall of fungi composed of?

Chitin

Name some examples of decomposers.

Fungi and certain bacteria

What do decomposers secrete onto their food source?

Enzymes

What role do saprophytic microorganisms play in sewage treatment?

They secrete enzymes to digest solid organic matter into soluble, harmless substances.

What enzyme contained in flour digests starch to sugar?

Amylase

What two products are produced when yeast ferments sugar in the absence of oxygen?

Alcohol and CO2

Name the two types of bacteria used to ferment milk in yoghurt production.

Lactobacillus bulgaricus and Streptococcus thermophilus

What acid does Lactobacillus convert lactose to?

Lactic acid

What does lactic acid cause milk protein (casein) to do?

Curdle

What is a fermenter?

A large steel cylindrical tank designed to keep its internal environment favorable for the desired biological process

Name the three systems of the fermenter.

Cooling system, aeration system, impeller

What is the size range of a fermenter for large-scale production of Penicillin?

100000-150000 L

What is the main carbohydrate added to a fermenter for the growth of the fungus penicillium?

Lactose

What is the optimum pH and temperature conditions required in a fermenter for large-scale production of Penicillin

pH: 5-6 Temperature: 26°C

What does SCP stand for?

Single-cell Protein

Which fungus is mycoprotein produced from?

Fusarium

What is ecology?

The study of interactions among organisms and between organisms and their environment.

What is the ultimate source of energy?

The sun

What is a population?

A group of individuals of the same species occupying a given area.

What is a community?

Different populations of plants and animals live together and interact within the same environment.

What is an ecosystem?

An ecological system formed by the interaction of living organisms and their non-living environment.

What are producers?

Mainly green plants that manufacture complex organic food substances from raw materials.

What are consumers?

Organisms that obtain energy from other organisms on which they feed.

What are herbivores?

Organism that feed only on plant materials.

What are carnivores?

Organism Feed on primary Herbivores Feed on primary consumers, consumers also known as carnivores.

What are decomposers?

Organisms that act on dead organisms and enable the materials locked up in them to be returned to the physical environment.

What is a food chain?

A series of organisms through which energy is transferred in material form.

What does the arrows in a food chain represent?

Energy transferred from one trophic level to another

What is a trophic level?

Each stage in a food chain

What is a food web?

The combination of several food chains to show interactions between organisms.

What are ecological pyramids?

They represents the number of organisms occupying each trophic level, biomass or total energy level.

What are Anopheles mosquito known for?

Malaria is caused by certain species of Plasmodium which is transmitted by female Anopheles mosquito.

What is parasitism?

An association between two organisms such that one organism (the parasite) lives on or in the body of another organism (the host).

Name some ways to control malaria.

Sleep under mosquito nets, use mosquito repellants, filling and draining of breeding places of mosquitoes, use of Insecticides, adding a layer of all in stagnant water, adding small fish in ponds or lakes, fumigating

What are the effects of humans on the ecosystem?

Deforestation, pollution (air, water, noise), global warming, use of insecticides and pesticides

What is the meaning of Eutrophication.

Water pollution by sewage, by inorganic waste and by nitrogen-containing fertilizers

What is the meaning of acid rain.

Air pollution by acidic gases (sulfur dioxide, Carbon monoxide, oxides of nitrogen

List reasons for conservation of species.

Ensure the protection of species and prevents their extinction, maintains a large gene pool, maintains stable and balanced ecosystem, ensure conservation of marine life

How does recycling reduces waste disposal and pollution?

Recycling (treatment) of sewage saves water, saves energy and money

What is mitosis?

cell division giving rise to genetically identical cells in which the chromosome number is maintained.

What is asexual reproduction?

The production of new individuals that does not involve fertilization, and the offsprings are genetically identical from the parent.

What is meiosis?

A reduction division in which the chromosome number is halved from diploid to haploid.

What are main parts of a flower?

Pedicel, receptacle, sepals, petals, stamens, pistil, ovary, ovule

What is pollination?

The transfer of pollen grains from the anther to the stigma.

Give the two types of pollination.

Self-pollination (of the same flower or the same plant). Cross-pollination (pollen grains are transferred to another plant of the same kind)

List the major mechanisms of pollination.

Wind pollination, Insect pollination

What are pollen grains like from wind-pollinated flowers?

Pollen grain are abundant, are small, dry, smooth and light

What does the term Fertilization means in plants?

Fertilization occurs when the male gamete fuses with the nucleus of the female gamete to produce a diploid zygote.

Post-fertilization changes

whole ovule develops in seed, zygote develops in embryo plumule + radicle + cotyledons, endosperm nucleus endosperm, integuments develops in testa and tegmen, svule stalk develops to seed stalk (funicle), Ovary develops in fruit, Ovary wall develops in fruit wall (pericarp), stigma, style, stamens, petals wither and fall off.

List what a dispersed seed contains.

plumule, endosperm, cotyledon, stalk, radicle, hilum, micropyle

Why is dispersal is necessary?

avoid overcrowding, overcrowding and competition for food and light with the parent plants, enable plants to colonise new and favourable habitats and reduce the spread of disease.

What are the dispersal mechanism.

Dispersal by wind, animals, water, explosive mechanism

What are the factors affecting germination

Water, oxygen, suitable temperature

What are enzyme activities happens in the seed?

anylase breaks down Startch for matase that produces glucose, Lipase breaks down Fats and produces fatty acids + glycerol, Proteases breaks down Proteins to produce amino acids

What are the types of germination?

Epigeal germination and Hypogeal germination

A gamete is formed by which cell division.

Gametes are formed by meiosis.

What is the site where the egg is fertilised by a sperm cell in female reproductive system?

Oviducts-Also known as the fallopian tube

What does Cervix do?

A drcular ring of muscles which assist and control child birth.

What does Vagina do?

A canal which assist child birth, urination and allows deposition of semen during sexual intercourse

What is a menstrual cycle?

A cycle which last for 28 days when one mature egg cell (ovum) is released.

Wht happens to hormone level during Menstruation?

Repair of uterine wall then ovulation, utereus lining thickens

What is ovulation?

This is the process where a mature egg is released into the oviduct funnel.

List some of the hormones secreted by the anterior pituitary gland.

Follicle stimulating Hormone (FSH), Oestrogen stimulates the development of the follicles in the ovaries and,Luteinising hormone (LH) It causes ovulation and also causes the formation of the corpus luteum.

What is amniotic fluid?

The amniotic sac which encloses the embryo and hold the amniotic fluid. The fluid filled space is known as the amniotic cavity.

Function of the amniotic fluid

It supports and protects the fetus before birth, It is a shock absorber and protects the fetus against mechanical injury. Lubricates and reduces friction in the vagina. Allows the fetus to move fredy during growth and development.

function of the Placenta

Allows dissolved food and oxygen to diffuse from the mother's blood to embryo's. metabolic waste products diffuse from the Embryonic Blood capillaries into the mother's bloodstream.

Function of the umbilical cord

Contains blood vessels that carry oxygenated blood and food substances from the placenta to the fetus and deoxgenated blood from the fetus to placenta

Special dietary needs of pregnant women

Eat food rich in Calcium, Iron, Essential fatty acids, proteins, Vitamins and minerals.

Advantages of breast milk over bottle milk

It is at the right temperature for the baby, it contain antibodies that protect the day by and it is inexpensive and readily available.

List some methods of birth control

Abstinence during fertile period, Chemical (Spermicides) pills sperm, Mechanical Condom, Intra- Uterine Device (IUD), Hormone: pills and Surgical

List some sexually transmitted disease

Syphilis and Acquired Immune Deficiency Syndrome (AIDS)

Genetics is the study of _

heredity

What unit of Heredity contains DNA and genes?

chromosome

What is a Gene?

A small segment of DNA in a chromosome where a piece of genetic information is stored

Different forms of the same gene are called _.

alleles

Why does organism has Dominant allele.

allele which is always expressed in the appearance

What is Homozygous?

Having both alleles the same (eg TT and GG)

What is Heterozygous?

Having one capital letter allele (dominant trait) and one small letter allele. Eg Tt and Gg.

Define Recessive allele

The effects of this allele are only seen when it is present on both chromosomes

What is Monohybrid Inheritance

a type of inheritance involving only one pain of Contrasting characters.

Phenotype

refers to the expressed trait, eg the outward appearance or visible character of an organism

Genotype

the genetic make-up of an organism, ie the genes and their respective alleles.

What is a Test cross.

A genetic test that includes crossing a male with a female by fertilization where four offsprings are produced.

Incomplete dominance:

This is when both allele exert their effects so that a hybrid has a phenotype that is intermediate between parents.

human populationblood groups: A, B, AB and O

This is an example of multiple alleles. where alleles for group A, B and O may be designated IA, IB and I° respectively. If IA and IB are dominant over I°; but A and IB are neither dominant over the other

What is a chromosome?

he chromosome which determines the sex of a Human beings have 46 chromosomes in each cell. The last pair of chromosome (nos 23) is known as the sex

What is Mutation?

Mutation is the sudden or spontaneous change in gene structure or a chromosome, or even the chromosome number, is modified or altered.

What are the types of Mutation?

Albinism and Down's Syndrome and sickle-cell anaemia

What are Mutagenic agents

Substances or agents that cause a mutation are known as a mutagen

What is Variations

Variations are differences in traits or characteristics between individuals of the same species

What type of Variations are.

Continuous variation(range of measurements from one extreme to another) and Discontinuous variation(fall into distinct categories).