Welcome to Class !!
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In today’s Agricultural Science class, We will be learning about Crop Improvement. We hope you enjoy the class!
- Meaning of crop improvement
- Aims of crop improvement
- Methods of crop improvement
- Processes of crop improvement
MEANING OF CROP IMPROVEMENT
Crop improvement is defined as the science that deals with the development of new crop varieties with superior quality and quantity.
AIMS OF CROP IMPROVEMENT
- To increase yield
- To improve the quality of produce
- To adapt to climatic conditions
- To increase resistance to diseases
- To increase resistance to pests
- To meet the needs of growers
- To produce crops with uniform agronomic characteristics
- To breed crops with early maturity
- To improve the nutrient value of the produce
- To meet the needs of consumers
- What is crop improvement?
- State five aims of crop improvement
DEFINITION OF SOME GENETIC TERMS
- Genes: These are hereditary unit or basic unit of inheritance
- Chromosomes: They are rod or thread-like bodies found in the nucleus of a cell
- Character or Trait: These are the inheritance attributes or features possessed by an organism e.g. seed colour
- Gamete: It is a mature sex cell
- Zygote: is a single cell formed as a result of the union of a male gamete with a female gamete
- Allelomorphs (allele): These are pairs of genes on the position of a chromosome that controls a character
- Phenotype: is the sum total of all observable features of an organism i.e. physical, physiological and behavioural traits e.g. height, weight and skin colour
- Genotype: is the sum total of the genes inherited from a parent.
- Dominant character: This is a trait or character that is expressed in an offspring when two individuals with contrasting character or traits are crossed
- Recessive character: This is the character or trait which does not produce the effect in the presence of dominant character.
- Homozygous: An individual is said to be homozygous if it has two similar genes for the same character, i.e. the pair of gene controlling a given pair of contrasting characteristics are identical e.g. TT for height T for Tall or tt for height t for short
- Heterozygous: An individual is said to be heterozygous if the two members of a pair of genes controlling a pair of contrasting characters are different. e.g. Tt for height T for Tall and t for short
- Filial generation: The offspring of parents make up the filial generation. The first, second and third filial generations are represented by F1, F2 and F3 respectively.
- Hybrid: These are offsprings from a cross between parents that are genetically different but of the same species.
- Hybridization: This is the crossing of plants with contrasting characters. There are two major types of hybridization, this includes Monohybridization and Dihybridization.
Dihybridization involves the crossing of plants with two pairs of contrasting characters.
Monohybridization involves the crossing of two pure traits.
16. Mutation: is a change in the genetic make-up of an organism resulting in a new characteristic that is inheritable.
- Define; A. Gene B. Chromosome C. Trait
- Explain; A. Mutation B. Hybridization C. Genotype
We have come to the end of this class. We do hope you enjoyed the class?
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
In our next class, we will continue learning about Crop Improvement. We are very much eager to meet you there.
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